JavaWeb_(Hibernate框架)Hibernate中数据查询语句SQL基本用法

 

 

本文展示三种在Hibernate中使用SQL语句进行数据查询基本用法

　　1、基本查询

　　2、条件查询

　　3、分页查询

 

package com.Gary.dao;

import java.util.List;

import org.hibernate.Session;
import org.hibernate.Transaction;
import org.hibernate.query.NativeQuery;

import com.Gary.domain.User;
import com.Gary.utils.HibernateUtils;

public class SQLDao {

    public void find()
    {
        Session session = HibernateUtils.getSession();
        Transaction beginTransaction = session.beginTransaction();
        
        //开始进行SQL查询
        String sql = "select * from user";
        
        //创建sql查询对象
        NativeQuery query = session.createSQLQuery(sql);
        query.addEntity(User.class);
        
        //接收list
        List<User> list = query.list();
        //接收单一返回值  query.uniqyeResult();
        
        //输出第一个成员姓名
        System.out.println(list.get(0).getUsername());
        //结束SQL查询
        
        beginTransaction.commit();
        session.close();
        
    }
    
    //SQL条件查询
    public void find2()
    {
        Session session = HibernateUtils.getSession();
        Transaction beginTransaction = session.beginTransaction();
        
        //开始进行SQL查询
        String sql = "select * from user where id = ?";
        //创建SQL查询对象
        NativeQuery query = session.createSQLQuery(sql);
        //封装参数,给第一个?赋值
        query.setParameter(1, "1");
        
        query.addEntity(User.class);
        //唯一返回值
        User user = (User) query.uniqueResult();
        System.out.println(user);
        //结束SQL查询
        
        beginTransaction.commit();
        session.close();
        
    }
    
    
    //SQL分页查询
    public void find3()
    {
        Session session = HibernateUtils.getSession();
        Transaction beginTransaction = session.beginTransaction();
        
        //开始进行SQL查询
        String sql = "select * from user limit ? , ?";
        //创建SQL查询对象
        NativeQuery query = session.createSQLQuery(sql);
        //封装参数,给第一个?赋值
        query.setParameter(1, 0);
        //同理
        query.setParameter(2, 2);
        query.addEntity(User.class);
        //唯一返回值
        List<User> list = query.list();
        System.out.println(list.get(0).getUsername());
        //结束SQL查询
        
        beginTransaction.commit();
        session.close();
        
    }
    
}

 

　　数据库user表

 

　　向数据库中添加假数据

　　

 

1、SQL基本查询

　　//开始进行SQL查询
　　String sql = "select * from user";
        
　　//创建sql查询对象
　　NativeQuery query = session.createSQLQuery(sql);
　　query.addEntity(User.class);

 

　　SQLDao.java向数据库发起查询请求

public void find()
    {
        Session session = HibernateUtils.getSession();
        Transaction beginTransaction = session.beginTransaction();
        
        //开始进行SQL查询
        String sql = "select * from user";
        
        //创建sql查询对象
        NativeQuery query = session.createSQLQuery(sql);
        query.addEntity(User.class);
        
        //接收list
        List<User> list = query.list();
        //接收单一返回值  query.uniqyeResult();
        
        //输出第一个成员姓名
        System.out.println(list.get(0).getUsername());
        //结束SQL查询
        
        beginTransaction.commit();
        session.close();
        
    }

 

　　

 

package com.Gary.dao;

import java.util.List;

import org.hibernate.Session;
import org.hibernate.Transaction;
import org.hibernate.query.NativeQuery;

import com.Gary.domain.User;
import com.Gary.utils.HibernateUtils;

public class SQLDao {

    public void find()
    {
        Session session = HibernateUtils.getSession();
        Transaction beginTransaction = session.beginTransaction();
        
        //开始进行SQL查询
        String sql = "select * from user";
        
        //创建sql查询对象
        NativeQuery query = session.createSQLQuery(sql);
        query.addEntity(User.class);
        
        //接收list
        List<User> list = query.list();
        //接收单一返回值  query.uniqyeResult();
        
        //输出第一个成员姓名
        System.out.println(list.get(0).getUsername());
        //结束SQL查询
        
        beginTransaction.commit();
        session.close();
        
    }
    
}

 

 

2、SQL条件查询

        //开始进行SQL查询
        String sql = "select * from user where id = ?";
        //创建SQL查询对象
        NativeQuery query = session.createSQLQuery(sql);
        //封装参数,给第一个?赋值
        query.setParameter(1, "1");
        
        query.addEntity(User.class);

 

　　SQLDao.java向数据库发起查询请求

public void find2()
    {
        Session session = HibernateUtils.getSession();
        Transaction beginTransaction = session.beginTransaction();
        
        //开始进行SQL查询
        String sql = "select * from user where id = ?";
        //创建SQL查询对象
        NativeQuery query = session.createSQLQuery(sql);
        //封装参数,给第一个?赋值
        query.setParameter(1, "1");
        
        query.addEntity(User.class);
        //唯一返回值
        User user = (User) query.uniqueResult();
        System.out.println(user);
        //结束SQL查询
        
        beginTransaction.commit();
        session.close();
        
    }

 

 

package com.Gary.dao;

import java.util.List;

import org.hibernate.Session;
import org.hibernate.Transaction;
import org.hibernate.query.NativeQuery;

import com.Gary.domain.User;
import com.Gary.utils.HibernateUtils;

public class SQLDao {

    public void find()
    {
        Session session = HibernateUtils.getSession();
        Transaction beginTransaction = session.beginTransaction();
        
        //开始进行SQL查询
        String sql = "select * from user";
        
        //创建sql查询对象
        NativeQuery query = session.createSQLQuery(sql);
        query.addEntity(User.class);
        
        //接收list
        List<User> list = query.list();
        //接收单一返回值  query.uniqyeResult();
        
        //输出第一个成员姓名
        System.out.println(list.get(0).getUsername());
        //结束SQL查询
        
        beginTransaction.commit();
        session.close();
        
    }
    
    
    public void find2()
    {
        Session session = HibernateUtils.getSession();
        Transaction beginTransaction = session.beginTransaction();
        
        //开始进行SQL查询
        String sql = "select * from user where id = ?";
        //创建SQL查询对象
        NativeQuery query = session.createSQLQuery(sql);
        //封装参数,给第一个?赋值
        query.setParameter(1, "1");
        
        query.addEntity(User.class);
        //唯一返回值
        User user = (User) query.uniqueResult();
        System.out.println(user);
        //结束SQL查询
        
        beginTransaction.commit();
        session.close();
        
    }
    
}

 

 

3、SQL分页查询

　　//开始进行SQL查询
　　String sql = "select * from user limit ? , ?";
　　//创建SQL查询对象
　　NativeQuery query = session.createSQLQuery(sql);
　　//封装参数,给第一个?赋值
　　query.setParameter(1, 0);
　　//同理
　　query.setParameter(2, 2);
　　query.addEntity(User.class);
　　//唯一返回值
　　List<User> list = query.list();

 

　　SQLDao.java向数据库发起查询请求

//SQL分页查询
    public void find3()
    {
        Session session = HibernateUtils.getSession();
        Transaction beginTransaction = session.beginTransaction();
        
        //开始进行SQL查询
        String sql = "select * from user limit ? , ?";
        //创建SQL查询对象
        NativeQuery query = session.createSQLQuery(sql);
        //封装参数,给第一个?赋值
        query.setParameter(1, 0);
        //同理
        query.setParameter(2, 2);
        query.addEntity(User.class);
        //唯一返回值
        List<User> list = query.list();
        System.out.println(list.get(0).getUsername());
        //结束SQL查询
        
        beginTransaction.commit();
        session.close();
        
    }

 

 

package com.Gary.dao;

import java.util.List;

import org.hibernate.Session;
import org.hibernate.Transaction;
import org.hibernate.query.NativeQuery;

import com.Gary.domain.User;
import com.Gary.utils.HibernateUtils;

public class SQLDao {

    public void find()
    {
        Session session = HibernateUtils.getSession();
        Transaction beginTransaction = session.beginTransaction();
        
        //开始进行SQL查询
        String sql = "select * from user";
        
        //创建sql查询对象
        NativeQuery query = session.createSQLQuery(sql);
        query.addEntity(User.class);
        
        //接收list
        List<User> list = query.list();
        //接收单一返回值  query.uniqyeResult();
        
        //输出第一个成员姓名
        System.out.println(list.get(0).getUsername());
        //结束SQL查询
        
        beginTransaction.commit();
        session.close();
        
    }
    
    //SQL条件查询
    public void find2()
    {
        Session session = HibernateUtils.getSession();
        Transaction beginTransaction = session.beginTransaction();
        
        //开始进行SQL查询
        String sql = "select * from user where id = ?";
        //创建SQL查询对象
        NativeQuery query = session.createSQLQuery(sql);
        //封装参数,给第一个?赋值
        query.setParameter(1, "1");
        
        query.addEntity(User.class);
        //唯一返回值
        User user = (User) query.uniqueResult();
        System.out.println(user);
        //结束SQL查询
        
        beginTransaction.commit();
        session.close();
        
    }
    
    
    //SQL分页查询
    public void find3()
    {
        Session session = HibernateUtils.getSession();
        Transaction beginTransaction = session.beginTransaction();
        
        //开始进行SQL查询
        String sql = "select * from user limit ? , ?";
        //创建SQL查询对象
        NativeQuery query = session.createSQLQuery(sql);
        //封装参数,给第一个?赋值
        query.setParameter(1, 0);
        //同理
        query.setParameter(2, 2);
        query.addEntity(User.class);
        //唯一返回值
        List<User> list = query.list();
        System.out.println(list.get(0).getUsername());
        //结束SQL查询
        
        beginTransaction.commit();
        session.close();
        
    }
    
}